Prior art of possible relevance to in-line valves includes U.S. Pat. Nos. 3,092,132 issued June 4, 1963 to Guy et al; 3,792,716 issued Feb. 19, 1974 to Sime et al; and 3,825,026 issued July 23, 1974 to Salerno et al. Prior art dealing with bleed air and/or stall characteristics of turbine engines includes U.S. Pat. Nos. 3,915,587 issued Oct. 28, 1975 to Rannenberg and 4,117,668 issued Oct. 3, 1978 to Elsaesser et al.
Those knowledgeable in the field of turbine engines have long been aware of the deleterious effect of a so-called "compressor section stall" . As a consequence, a great deal of effort has been expended in developing various proposals to avert the difficulty.
Many of these proposals involve modification of fuel flow to the combustor section of the engine upon the onset of a stall coupled with an increase in the rate of flow of bleed air from one or more stages of the compressor section.
While such proposals are effective, they have been hampered to some degree, by the difficulty in detecting an impending stall in the compressor section of the engine. In particular, the difficulty incurred in detecting an impending stall has resulted in, in some instances, insufficient time for mechanical instrumentalities as, for example, bleed air valves for the turbine compressor stage to respond to prevent a stall, and thus the consequences of the stall.
The present invention is directed to overcoming the above problem.